SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49e45ce0ad3da1737cf816cf7608835e0864c9bf5e8e83eb38d28ed009fb47cb' 
  AND token = 'AAZqLBs5kwAIUur5+ydCzjIItohfbzoiyBQJ3hXQ0/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}